<!DOCTYPE HTML>
<html> 
<head>
<script language="javascript">
function draw() {
  var ctx = document.getElementById('myCanvas').getContext('2d');
  for (var i = 0; i < 12; i++){
    ctx.strokeStyle="red";
    ctx.lineWidth = 1+i;
    ctx.beginPath();
    ctx.moveTo(5,5+i*14);
    ctx.lineTo(140,5+i*14);
    ctx.stroke();
  }
}
window.onload=function(){
    draw();
}
</script>
</head>
<body>
<canvas id="myCanvas" width="300" height="200"></canvas>
</body>
</html>
